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Yiming Gong - One of the best experts on this subject based on the ideXlab platform.
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Late Devonian palaeobiogeography of marine organic walled phytoplankton
Palaeogeography Palaeoclimatology Palaeoecology, 2019Co-Authors: Zhen Shen, Junjun Song, Thomas Servais, Yiming GongAbstract:Abstract Acritarchs and prasinophytes have generally been considered as organic-walled phytoplankton, and their distribution patterns play a significant role in palaeogeographical and palaeoclimatical reconstructions. In this paper the palaeobiogeography of Late Devonian phytoplankton (mainly Famennian) is quantitatively analyzed based on a global database consisting of 95 genera from 15 geographical units. The data are analyzed using cluster analysis, nonmetric multidimensional scaling, and minimum spanning tree analysis using the Jaccard, Ochiai, Kulczynski, and Yule's Y similarity coefficients. The results show that there was provincialism in the Late Devonian and three phytoplankton palaeobiogeographical realms could be identified: the West Gondwana, East Gondwana, and Boreal realms. There is a high degree of similarity between phytoplankton assemblages in East Gondwana (especially those in Australia and Iran) and Euramerica. Portugal (of the Iberian-Armorican block) was situated to the north of Algeria and probably acted as a stepping stone between Euramerica and West Gondwana. The closed oceanic surface circulation pattern in the Proto-Tethys Ocean between Euramerica and East Gondwana might have hindered the exchange of phytoplankton between East and West Gondwana. The phytoplankton province that had been typically confined to the higher latitudes was still present, while its characteristic genera gradually dispersed into the lower latitudes in the Late Devonian. There is a high similarity between phytoplankton assemblages from the western Junggar of Xinjiang, NW China and Euramerica. Latitude- and current-influenced palaeotemperature and oceanic circulation patterns are considered to have been the major determinants of the geographical distribution and evolution of marine phytoplankton in the Late Devonian.
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Late Devonian benthic ostracods from western Junggar, NW China: Implications for palaeoenvironmental reconstruction
Geological Journal, 2019Co-Authors: Junjun Song, S. Crasquin, Yiming GongAbstract:This study focuses on palaeoecology and palaeobiogeography of Late Devonian ostracods based on more than 4500 carapaces collected from sections in the western Junggar, NW China. According to the ostracod faunas from the Hongguleleng Formation, three ecological assemblages for an open oceanic island arc are proposed, i.e., OA1 (Ostracod Assemblage-1), OA2 (Ostracod Assemblage-2) and OA3 (Ostracod Assemblage-3). They characterize foreshore, nearshore and offshore, respectively. Water energy should be the first environmental factor controlling the composition of the ostracod assemblages from the Lower Member of the Hongguleleng Formation, and salinity fluctuations could be also involved. Many cosmopolitan species were present in the diversified ostracod faunas of the Hongguleleng Formation, suggesting possible biogeographic relationships between the Kazakhstan PLate and South China, North America and Russian pLates. The ostracods from Late Devonian of the Kazakhstan PLate might migrate to the South China Block and Laurentia-Baltica by ocean currents and sea-level changes, which also implies that neritic faunal exchanges were possible along the Palaeo-Tethys during the Late Devonian.
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Late Devonian carbon isotope chemostratigraphy: A new record from the offshore facies of South China
Global and Planetary Change, 2019Co-Authors: Xinsong Zhang, Michael M. Joachimski, D. Jeffrey Over, Cheng Huang, Yiming GongAbstract:Abstract We present a new biostratigraphically constrained carbon isotope record from the Lali section (South China) to document perturbations in the Late Devonian carbon cycle. Positive carbon isotope excursions (CIEs) are most important components of the Late Devonian long-term carbon isotope cycle: Frasnes (+2‰), Middlesex (+1‰), Lower Kellwasser (+3‰), Upper Kellwasser (+3‰) and Upper annulata (+1‰) events, as well as a small positive CIE (+1‰) in the Famennian expansa-aculeatus zones were recorded. It is noteworthy that no significant carbon isotope shifts are found for the Rhinestreet, Nehden, Condroz and Enkeberg events. The Late Devonian long-term carbon isotope curve from South China is in agreement with contemporaneous world-wide trends in Euramerica (Europe and North America) and Gondwana. Global data suggests a higher Famennian δ13Ccarb baseline (about +2.5 ‰) than that of the Frasnian (about +1‰). Previous studies have reLated the positive CIE to ocean anoxia, but its ultimate driver remains unclear. Other interpretations include the spread of land plants or increased tectonic activity, but these explanations are questionable due to the relative short durations of the CIEs compared to long-term processes of plant evolution and plant cover extension as well as tectonic movements.
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Late Devonian global ostracod palaeobiogeography
Lethaia, 2016Co-Authors: Junjun Song, Yiming GongAbstract:A global Late Devonian ostracod database is constructed, incorporating new materials from South China and Northwest China. Four palaeobiogeographical units (Cathaysia, North America, Europe and peri-Gondwana) are recognized during the Frasnian and five palaeobiogeographical units (Cathaysia, North America, Europe, Siberia and Australia) in the Famennian. Three controlling factors (climatic zonation, geographical isolation and global sea-level changes) are identified to have played roles in shaping the palaeogeographical regionalization of ostracod faunas in the Late Devonian. The ostracod palaeobiogeography in the Frasnian was mainly influenced by climatic zonation, while rapid changes in tectonic configuration in the Famennian drastically altered the global palaeobiogeography of ostracods. The palaeobiogeographical regionalization of ostracod faunas suggests that Laurussia and Gondwana continued to draw near during the Late Devonian, with the first collision occurring in Southern Central Europe in the Famennian. The South China pLate drifted northward to the Kazakhstan pLate away from the Australian pLate, which gradually became isoLated during the Famennian Stage.
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Late Devonian radiolarian-bearing siliceous rocks from the Karamay ophiolitic mélange in western Junggar: Implications for the evolution of the Paleo-Asian Ocean
Palaeogeography Palaeoclimatology Palaeoecology, 2016Co-Authors: Rui-wen Zong, Zizhang Wang, Tao Jiang, Yiming GongAbstract:Abstract Abundant Late Devonian radiolarians occur in the siliceous rocks of the Karamay ophiolitic melange in western Junggar. The siliceous rocks are interpreted as deposit in a remnant oceanic basin in view of their petrological and geochemical characteristics. New data suggest that the age of the Karamay ophiolitic melange can be extended from the Ordovician to Late Devonian, thus representing the youngest known oceanic crust in western Junggar, which indicates that the closure of the Paleo-Asian Ocean was at least after the Late Devonian in southern western Junggar. The Carboniferous formation capping the siliceous rocks units comprises, in ascending order, a broad regressive sequence from the abyssal–bathyal turbidites, littoral-neritic carbonates, and calcareous clastic rocks to molasse, indicating that the ocean–continent transformation probably occurred in the Devonian–Carboniferous transition or the early Early Carboniferous. The oceanic basin was filled with volcaniclastic turbidites in the Visean–Serpukhovian, and evolved into a residual sea basin in the Late Carboniferous. The final closure of the Paleo-Asian Ocean in western Junggar was marked by the emergence of molasse in the Late Late Carboniferous.
Deming Wang - One of the best experts on this subject based on the ideXlab platform.
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Pollen Organ Telangiopsis sp. of Late Devonian Seed Plant and Associated Vegetative Frond.
PLOS ONE, 2016Co-Authors: Deming Wang, Mei-cen MengAbstract:Pollen organ Telangiopsis sp., associated with but not attached to vegetative fronds, has been collected from the Upper Devonian (Famennian) Wutong Formation, Dongzhi County, Anhui Province, China. Fertile axes with terminal pollen organs are dichotomous for 2–4 times and may be proximally attached by fragmentary pinnules. Pollen organs are synangiate and borne on the top of a short stalk. Synangia are radial in symmetry and each consists of 4–8 elongate microsporangia fused at base. Microsporangia have a longitudinal dehiscence line and show a tapered apex. The associated stem is spiny and bears a vegetative frond which bifurcates once at the basalmost part. Frond rachises possess one order of pinna arranged alternately. Pinnules are borne alternately, planate, highly dissected, and equally dichotomous for 2–3 times. Comparisons among Late Devonian seed plants recognize several branching patterns in the fertile fronds/axes bearing terminal pollen organs. Telangiopsis sp. reinforces that the Late Devonian pollen organs are synangiate usually with basally fused microsporangia. It is suggested that the evolutionary divergence of radial and biLateral symmetries of pollen organs may have occurred in the Famennian, when the earliest seed plants evolved planate and sometimes laminate pinnules.
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A Late Devonian fertile organ with seed plant affinities from China.
Scientific Reports, 2015Co-Authors: Deming Wang, Mei-cen MengAbstract:Seed plants underwent first major evolutionary radiation in the Late Devonian (Famennian), as evidenced by the numerous ovules described to date. However, the early pollen organs are underrepresented, so that their structure and evolution remain poorly known. Here we report a new taxon of pollen organ Placotheca minuta from the Late Devonian. The synangium consists of many basally and more or less Laterally fused microsporangia borne on the margin of a pad. The prepollen is spherical and trilete. The appearance of Famennian synangia especially in Placotheca does not support the current understanding that the earliest pollen organs closely resembled the fructifications of the ancestral progymnosperms. Placotheca indicates earlier diversification of pollen organs than previously expected and is highly derived among the early pollen organs with trilete prepollen. It is suggested that, immediately after the origination of seed plants, pollen organs had evolved at a rapid rate, whereas their prepollen remained primitively spore-like.
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A new Late Devonian genus with seed plant affinities.
BMC evolutionary biology, 2015Co-Authors: Deming Wang, Le LiuAbstract:Many ovules of Late Devonian (Famennian) seed plants have been well studied. However, because few taxa occur with anatomically preserved stems and/or petioles, the vascular system of these earliest spermatophytes is little understood and available data come mostly from Euramerica. There remains great controversy over the anatomical differentiation of Late Devonian and Carboniferous seed plant groups of Buteoxylonales, Calamopityales and Lyginopteridales. Protostele evolution of these early spermatophytes needs more research. A new taxon Yiduxylon trilobum gen. et sp. nov. with seed plant affinities has been discovered in the Upper Devonian (Famennian) Tizikou Formation of Hubei Province, China. It is represented by stems, helically arranged and bifurcate fronds with two orders of pinnae and planate pinnules. Both secondary pinnae and pinnules are borne alternately. Stems contain a small protostele with three primary xylem ribs possessing a single peripheral protoxylem strand. Thick secondary xylem displays multiseriate bordered pitting on the tangential and radial walls of the tracheids, and has biseriate to multiseriate and high rays. A narrow cortex consists of inner cortex without sclerotic nests and sparganum-type outer cortex with peripheral bands of vertically aligned sclerenchyma cells. Two leaf traces successively arise tangentially from each primary xylem rib and they divide once to produce four circular-oval traces in the stem cortex. Four vascular bundles occur in two C-shaped groups at each petiole base with ground tissue and peripheral bands of sclerenchyma cells. Yiduxylon justifies the assignment to a new genus mainly because of the protostele with protoxylem strands only near the periphery of primary xylem ribs, leaf trace origination and petiolar vascular supply structure. It shares many definitive characters with Calamopityales and Lyginopteridales, further underscoring the anatomical similarities among early seed plants. The primary vascular system, pycnoxylic-manoxylic secondary xylem with bordered pits on both tangential and radial walls of a tracheid and leaf trace divergence of Yiduxylon suggest transitional features between the early spermatophytes and ancestral aneurophyte progymnosperms.
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An anatomically preserved arborescent lycopsid, Sublepidodendron songziense (Sublepidodendraceae), from the Late Devonian of Hubei, China
American journal of botany, 2002Co-Authors: Qi Wang, Deming Wang, Shougang Hao, David L. DilcherAbstract:Sublepidodendron is a common megafossil plant in the Late Devonian of China, but historically the generic delimitation based on leaf bases masked its true systematic position. A reinvestigation of S. songziense from the Late Devonian Hsiehchingssu Formation, Hubei, China, provides new insights into its internal anatomy and reproductive morphology. This arborescent lycopsid is characterized by small, vertically elongated leaf bases arranged in spirals, presence of false leaf scars, possibly bearing separate cones, and association with a stigmarian rhizomorph. The potential for organic connections of these detached organ genera has been noted for other Sublepidodendron species. The anatomy of S. songziense axes from two levels reveals that the thinner axis may bear an ectophloic siphonostele with a filamentous pith and an outer cortex. The thicker axis has a siphonostele with a branch gap, two-zoned pith with secondary thickenings, multiseriate rays across secondary xylem, a thick periderm, and primary and secondary tracheid walls characterized by "Williamson's striations." Similarities to synapomorphies of Diaphorodendraceae and Lepidodendraceae suggest that S. songziense bears a closer affinity to Lepidodendrales rather than Protolepidodendrales, as formerly thought. Widespread occurrence of Sublepidodendron implies that phylogenetically advanced arborescent lycopsids must have diverged by the Late Devonian.
Mei-cen Meng - One of the best experts on this subject based on the ideXlab platform.
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Pollen Organ Telangiopsis sp. of Late Devonian Seed Plant and Associated Vegetative Frond.
PLOS ONE, 2016Co-Authors: Deming Wang, Mei-cen MengAbstract:Pollen organ Telangiopsis sp., associated with but not attached to vegetative fronds, has been collected from the Upper Devonian (Famennian) Wutong Formation, Dongzhi County, Anhui Province, China. Fertile axes with terminal pollen organs are dichotomous for 2–4 times and may be proximally attached by fragmentary pinnules. Pollen organs are synangiate and borne on the top of a short stalk. Synangia are radial in symmetry and each consists of 4–8 elongate microsporangia fused at base. Microsporangia have a longitudinal dehiscence line and show a tapered apex. The associated stem is spiny and bears a vegetative frond which bifurcates once at the basalmost part. Frond rachises possess one order of pinna arranged alternately. Pinnules are borne alternately, planate, highly dissected, and equally dichotomous for 2–3 times. Comparisons among Late Devonian seed plants recognize several branching patterns in the fertile fronds/axes bearing terminal pollen organs. Telangiopsis sp. reinforces that the Late Devonian pollen organs are synangiate usually with basally fused microsporangia. It is suggested that the evolutionary divergence of radial and biLateral symmetries of pollen organs may have occurred in the Famennian, when the earliest seed plants evolved planate and sometimes laminate pinnules.
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A Late Devonian fertile organ with seed plant affinities from China.
Scientific Reports, 2015Co-Authors: Deming Wang, Mei-cen MengAbstract:Seed plants underwent first major evolutionary radiation in the Late Devonian (Famennian), as evidenced by the numerous ovules described to date. However, the early pollen organs are underrepresented, so that their structure and evolution remain poorly known. Here we report a new taxon of pollen organ Placotheca minuta from the Late Devonian. The synangium consists of many basally and more or less Laterally fused microsporangia borne on the margin of a pad. The prepollen is spherical and trilete. The appearance of Famennian synangia especially in Placotheca does not support the current understanding that the earliest pollen organs closely resembled the fructifications of the ancestral progymnosperms. Placotheca indicates earlier diversification of pollen organs than previously expected and is highly derived among the early pollen organs with trilete prepollen. It is suggested that, immediately after the origination of seed plants, pollen organs had evolved at a rapid rate, whereas their prepollen remained primitively spore-like.
Le Liu - One of the best experts on this subject based on the ideXlab platform.
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A new Late Devonian genus with seed plant affinities.
BMC evolutionary biology, 2015Co-Authors: Deming Wang, Le LiuAbstract:Many ovules of Late Devonian (Famennian) seed plants have been well studied. However, because few taxa occur with anatomically preserved stems and/or petioles, the vascular system of these earliest spermatophytes is little understood and available data come mostly from Euramerica. There remains great controversy over the anatomical differentiation of Late Devonian and Carboniferous seed plant groups of Buteoxylonales, Calamopityales and Lyginopteridales. Protostele evolution of these early spermatophytes needs more research. A new taxon Yiduxylon trilobum gen. et sp. nov. with seed plant affinities has been discovered in the Upper Devonian (Famennian) Tizikou Formation of Hubei Province, China. It is represented by stems, helically arranged and bifurcate fronds with two orders of pinnae and planate pinnules. Both secondary pinnae and pinnules are borne alternately. Stems contain a small protostele with three primary xylem ribs possessing a single peripheral protoxylem strand. Thick secondary xylem displays multiseriate bordered pitting on the tangential and radial walls of the tracheids, and has biseriate to multiseriate and high rays. A narrow cortex consists of inner cortex without sclerotic nests and sparganum-type outer cortex with peripheral bands of vertically aligned sclerenchyma cells. Two leaf traces successively arise tangentially from each primary xylem rib and they divide once to produce four circular-oval traces in the stem cortex. Four vascular bundles occur in two C-shaped groups at each petiole base with ground tissue and peripheral bands of sclerenchyma cells. Yiduxylon justifies the assignment to a new genus mainly because of the protostele with protoxylem strands only near the periphery of primary xylem ribs, leaf trace origination and petiolar vascular supply structure. It shares many definitive characters with Calamopityales and Lyginopteridales, further underscoring the anatomical similarities among early seed plants. The primary vascular system, pycnoxylic-manoxylic secondary xylem with bordered pits on both tangential and radial walls of a tracheid and leaf trace divergence of Yiduxylon suggest transitional features between the early spermatophytes and ancestral aneurophyte progymnosperms.
Rui-wen Zong - One of the best experts on this subject based on the ideXlab platform.
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Late Devonian radiolarian-bearing siliceous rocks from the Karamay ophiolitic mélange in western Junggar: Implications for the evolution of the Paleo-Asian Ocean
Palaeogeography Palaeoclimatology Palaeoecology, 2016Co-Authors: Rui-wen Zong, Zizhang Wang, Tao Jiang, Yiming GongAbstract:Abstract Abundant Late Devonian radiolarians occur in the siliceous rocks of the Karamay ophiolitic melange in western Junggar. The siliceous rocks are interpreted as deposit in a remnant oceanic basin in view of their petrological and geochemical characteristics. New data suggest that the age of the Karamay ophiolitic melange can be extended from the Ordovician to Late Devonian, thus representing the youngest known oceanic crust in western Junggar, which indicates that the closure of the Paleo-Asian Ocean was at least after the Late Devonian in southern western Junggar. The Carboniferous formation capping the siliceous rocks units comprises, in ascending order, a broad regressive sequence from the abyssal–bathyal turbidites, littoral-neritic carbonates, and calcareous clastic rocks to molasse, indicating that the ocean–continent transformation probably occurred in the Devonian–Carboniferous transition or the early Early Carboniferous. The oceanic basin was filled with volcaniclastic turbidites in the Visean–Serpukhovian, and evolved into a residual sea basin in the Late Carboniferous. The final closure of the Paleo-Asian Ocean in western Junggar was marked by the emergence of molasse in the Late Late Carboniferous.
